Surgical devices, in particular absorbable monofilament sutures and ligatures and hemostatic ligating clips, made from p-dioxanone homopolymer are valuable commercial articles. This invention is directed to a means for providing p-dioxanone polymers that have properties that are different from those that can be obtained in the homopolymer. This invention thereby provides a means for extending the utility of p-dioxanone polymers.
P-dioxanone polymers are disclosed by Doddi et al. in U.S. Pat. No. 4,052,988, who also disclose and claim sutures and other surgical devices made from such polymers. In the paragraph bridging Columns 8 and 9 of the Doddi et al. patent, it is disclosed that lactide may be copolymerized with p-dioxanone to produce absorbable sutures.
Surgical filaments such as sutures and ligatures of p-dioxanone homopolymer are commercially available in the form of monofilaments. One of the desirable characteristics of a monofilament suture is to exhibit a combination of high strength (in the form of straight tensile and knot tensile strength) and good pliability. Monofilaments of p-dioxanone homopolymers are perceived by the surgeon as being rather stiff. One of the valuable advantages of this invention is that it provides p-dioxanone polymers that are more pliable and, in many cases, stronger than p-dioxanone homopolymer, thereby substantially enhancing the utility of p-dioxanone polymers.